"Short sellers have been selling into JD.com’s price weakness since mid-July with 7 million new shares shorted since July 15, up 23%," Ihor Dusaniwsky, managing director of predictive analytics at S3, said in an email.

Overall, short sellers have made $392 million in mark-to-market profits since January, most of which occurred during the second half of the year, Dusaniwsky added. S3 data shows JD.com is now the seventh-largest short in the Hong Kong/China region, with $1.03 billion of short interest.

Last month, JD.com, the second-largest Chinese e-commerce company after Alibaba, posted a loss of $0.23 per share on revenue of $18.5 billion. Analysts surveyed by Bloomberg were expecting a $0.12 per share gain on revenue of $19.31 billion.